Dhaka, Mar 23 (IANS): Thousands of Rohingya Muslims have lost their shelters after a massive fire ravaged refugee camps in Bangladesh's Coxs Bazar district, officials said.

The fire broke out on Monday afternoon at one of the camps and spread to four adjoining ones, Mohammad Shamsud Douza, deputy chief of the government's Refugee Relief and Repatriation Commission, told dpa news agency .

He said firefighters spent three hours battling the flames until evening, and it then took three more hours to bring the blaze under control.

An estimated 150,000 people had been living in the shanties, he said.

According to an initial estimate, more than 9,500 shanties have been destroyed, he added, though the full extent of damage would only be clear once the fire was completely extinguished.

No casualties have been reported so far, he said.

It was not clear how the fire originated, but witnesses said it spread quickly from one camp to the other.

The camps are home to hundreds of thousands of Rohingya Muslims who fled persecution in neighbouring Myanmar.

The UN High Commissioner for Refugees in a statement said humanitarian partners have mobilised hundreds of volunteers from nearby camps to support the firefighting and rescue efforts.

So far, the fire has affected shelters, health centres, distribution points and other facilities, the UN agency said.

More than 1 million Rohingya Muslims are living in shelters constructed mainly from polyethylene sheets and bamboo shafts in Cox's Bazar, some 300 km south of Dhaka.

Nearly 750,000 of them crossed the border after Myanmar launched a crackdown on the minority group in August 2017.